title: Effect of anticipation on knee kinematics during a stop-jump task.
abstract: Knee stability during a functional assessment of the stop-jump task is a key factor to determine if an athlete is adequately rehabilitated after knee ligamentous injury. This study aimed to investigate knee stability due to the effect of anticipation on landing maneuvers during planned and unplanned stop-jump tasks. Knee kinematics of ten healthy male participants were collected using an optical motion analysis system during stop-jump tasks. Stop jumps were performed in four different landing positions either in planned movement or in an unplanned movement on a signal triggered as participants passed through a photocell gate. Kinematic data at the time of foot strike at landing in the stop-jump considered for investigating the anticipation effect during the stop-jump tasks. Two-way multivariate analysis of variance (MANOVA) with repeated measures and stratified paired t-tests were conducted to compare the knee kinematics data between planned and unplanned tasks. Statistical significance was set at the p<0.05 level. External rotational angle showed a significant decrease in unplanned stop-jump tasks during forward (p<0.05) and right (p<0.05) jumps when compared to that of planned tasks. Flexion angle and abduction angle during forward, vertical and right jumps were significantly decreased in the unplanned tasks. Anticipation significantly influenced the landing maneuvers of stop-jump task. The results indicated that both planned and unplanned stop-jump tasks should be considered when monitoring the rehabilitation progress after a ligamentous injury.
authors.affiliation: Department of Orthopaedics and Traumatology, Prince of Wales Hospital, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China; The Hong Kong Jockey Club Sports Medicine and Health Sciences Centre, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China. Electronic address: dfong@cuhk.edu.hk.
authors.forename: Daniel Tik-Pui
authors.initials: DT
authors.lastname: Fong
authors.forename: Mak-Ham
authors.initials: MH
authors.lastname: Lam
authors.forename: Pik-Kwan
authors.initials: PK
authors.lastname: Lai
authors.forename: Patrick Shu-Hang
authors.initials: PS
authors.lastname: Yung
authors.forename: Kwai-Yau
authors.initials: KY
authors.lastname: Fung
authors.forename: Kai-Ming
authors.initials: KM
authors.lastname: Chan
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D009068:Movement / Q000502:physiology*; D016059:Range of Motion, Articular / Q000502:physiology*; D013177:Sports / Q000502:physiology*
keywords: Functional rehabilitation; Joint instability; Kinematics; Knee